Ah, calcium – that essential mineral we've all grown up hearing about. From building strong bones to orchestrating muscle contractions, calcium is a true VIP in our bodies. But when the scales tip too high, trouble brews. Join us on this journey as we unravel the intricacies of hypercalcemia in our furry companions.

Calcium: Not Just for Bones

Calcium isn't just for bone health; it's a maestro conducting a symphony of bodily functions. Think muscle contractions, heartbeats, and enzyme activation. Our bodies meticulously regulate blood calcium levels to keep the show running smoothly. But sometimes, things go awry.

Calcium Balance

Calcium has its tricks – it exists in different forms based on whether it's in action or at rest. Ionized calcium dances freely in the bloodstream, ready to perform its role. Bound calcium, carried by molecules like albumin, circulates with a purpose. Together, they make up total calcium. Bone is the storage warehouse, holding excess calcium. Our bodies manage this delicate dance through hormones – parathyroid hormone (PTH) and calcitriol (Vitamin D).

When Calcium Misbehaves

Picture this: the bones get a call to release calcium, either from excess PTH (parathyroid gland issue) or high PTH-related protein (PTH-rP, often related to tumors). Calcium departs, leaving weakened bones prone to fractures. Kidneys usually kick in to excrete excess calcium, but when PTH is high, they're a no-show. Kidney function deteriorates, calcium deposits wreak havoc in soft tissues, and inflammation ensues.

So, what throws this elegant system into disarray? Cue in PTH-rP, a mischief-maker produced by tumors. It skyrockets calcium levels, hinting at an undercover cancer operation.

The Hypercalcemia Hunt

Elevated calcium levels aren't just numbers – they signal underlying issues. Step into our diagnostic journey:

1. Check Ionized Calcium: Forget total calcium; focus on ionized calcium – the active player. If it's normal, we're in the clear.
2. Scan for Obvious Diseases: Hands-on checks for parathyroid issues, anal sac tumors, lymph nodes, and more. Review basic lab work for kidney trouble or multiple myeloma (cancer involving antibodies).
3. ACTH Stimulation Test: Investigate adrenal function for Addison's disease (hormone deficiency).
4. PTH and PTH-rP Levels: Assess parathyroid tumor or cancer clues. A high PTH level with high calcium suggests parathyroid trouble, while PTH-rP hints at cancer.
5. Tumor Search: Radiographs, ultrasounds, and bone marrow taps are next. Lymphoma often lurks as the culprit.

The Remedy Repertoire

Diet, bisphosphonates, prednisone, and saline diuresis are our allies:

• Dietary Therapy: Reduce calcium intake through diet, salt, fiber, or specialized diets.
• Bisphosphonates: These bone-preserving drugs dampen bone resorption, lowering blood calcium.
• Prednisone: This multi-talented drug assists kidneys in calcium disposal. But beware: it's a last resort for hypercalcemia caused by lymphoma.
• Saline Diuresis: Intravenous fluids and low-dose furosemide support kidney function.

A Parting Note

Hypercalcemia isn't to be taken lightly. Swift action is crucial, ensuring proper diagnosis and treatment. Don't hesitate to seek your vet's guidance. Remember, understanding hypercalcemia is like decrypting a calcium code – a puzzle that, when solved, restores harmony to your furry friend's health. 

Don't have a vet in your area yet? We can help you find a local veterinarian.

If you have more questions, the GeniusVets Telehealth platform will give you unlimited access to text and/or video calls with board-certified veterinarians! To learn more click here.